I think you already know what Page Rank is.If you don’t know then visit Wikipedia to know what is Page Rank and how it works.Now lets Continue.. In broad sense PageRank is a link building Algorithm and it determines the weight of a webpage by its Backlink number and their weights.
Page Rank values vary from 0 – 10, PR0 is the begging least value and PR10 is the Highest value.
Expected Next Google Page Rank update date
Next Page Rank Updated On Expected in March 2012
First Google January PageRank 2012 Update Time-frame: 30 Jan, 2012 – 2 Feb, 2012 Second Google June PageRank 2012 Update Time-frame: 30 Jun – 2 July, 2012 Third Google October PageRank 2012 Update Time-frame: 30 Oct – 8 Nov, 2012 Fourth Google December PageRank 2012 Update Time-frame: 1 Feb – 25 Feb 2013
Finally in my opinion you don’t need to know about Your PR to make a great site. so don’t bother about your sites Page Rank.I will say you Forget about the next Page Rank update date and try to Maximize your sites Backlinks or think about the next page on your website or blog.Last word: Don’t think too much about The Next Google Page Rank update date or your current Page Rank Status,Just build some quality backings and Leave rest to Google.